import java.util.LinkedList;
import java.util.Queue;

/**
 * @Author: Lenovo
 * @Date: 2024/7/18 22:07
 * @description:
 */
public class MyStackUseQueue {
    public Queue<Integer> queue1;
    public Queue<Integer> queue2;
    public MyStackUseQueue() {
        queue1 = new LinkedList();
        queue2 = new LinkedList();
    }

    public void push(int x) {
        if (!queue1.isEmpty()){
            queue1.offer(x);
        }else if (!queue2.isEmpty()){
            queue2.offer(x);
        }else{
            queue1.offer(x);
        }
    }

    public int pop() {
        if (empty()){
            return -1;
        }
        if (!queue1.isEmpty()){
            int size = queue1.size();
            for (int i=0;i<size-1;i++){
                queue2.offer(queue1.poll());
            }
            return queue1.poll();
        }else{
            int size = queue2.size();
            for(int i = 0;i<size-1;i++){
                queue1.offer(queue2.poll());
            }
            return queue2.poll();
        }
    }

    public int top() {
        if (empty()){
            return -1;
        }
        if (!queue1.isEmpty()){
            int size = queue1.size();
            int val = 0;
            for (int i = 0; i< size;i++){
                val = queue1.poll();
                queue2.offer(val);
            }
            return val;
        }else{
            int size = queue2.size();
            int val = 0;
            for(int i = 0;i<size;i++){
                val = queue2.poll();
                queue1.offer(val);
            }
            return val;
        }
    }

    public boolean empty() {
        return queue1.isEmpty()&&queue2.isEmpty();
    }
}
